I read here that you cannot pay for an action that does not have a Gold Cost. Can you bow more holdings than necessary to produce Gold for an action that does have a Gold Cost? For instance, let's say that I start my action phase somehow knowing that my opponent has a copy of Trade Embargo in his hand, and has enough Gold to play it. In order to prevent him from costing me gold, can I bow all of my holdings to pay for one attachment, then use the piles of gold in my pool to pay for other attachments and/or actions throughout my Action Phase? (I'm assuming that Trade Embargo does not affect gold production that has already occurred.)
If that is not acceptable, and you may not bow holdings to create more gold than you need, is it acceptable to bow a holding that by itself produces more gold than you need, if you have a less-productive holding that would also cover the cost? For instance, can I bow a Secluded Outpost to pay for a personality with 2GC, knowing that it's overpaying, even if I have a straightened holding that produces 2 gold that I could use instead, so that I can use the Interrupt on Secluded Outpost for an attachment?